Occurrence of killer Candida glabrata clinical isolates

"In this work we characterized the occurrence of killer activity in 64 Candida glabrata clinical isolates under different conditions. We found that only 6.25 % of the clinical isolates tested were positive for killer activity against a Saccharomyces cerevisiae W303 sensitive strain. Sensitivity of killer activity to different values of pH and temperatures was analyzed. We found that the killer activity presented by all isolates was resistant to every pH and temperature tested, although optimal activity was found at a range of pH values from 4 to 7 and at 37ºC. We did not observe extrachromosomal genetic elements associated with killer activity in any of the positive C. glabrata isolates. The killer effect was due to a decrease in viability and DNA fragmentation in sensitive yeast.

Oligonucleotides of Candida parapsilosis, detection method and kit comprising same

"The invention discloses an in vitro method for the identification of Candida parapsilosis, the sequences associated to said identification, as well as diagnosis kits for identifying Candida parapsilosis.""La invención describe un método in vitro de identificación de Candida parapsilosis , las secuencias asociadas a dicha identificación, así como kits de diagnóstico para identificar Candida parapsilosis.

Oligonucleotides of Candida tropicallis, detection method and kit comprising same

"The invention discloses an in vitro method for the identification of Candida tropicalis, the sequences associated to said identification, as well as diagnosis kits for identifying Candida tropicalis.""La invención describe un método in vitro de identificación de Candida tropicalis, las secuencias asociadas a dicha identificación, así como kits de diagnóstico para identificar Candida tropicalis.

Oligonucleotides of Candida albicans, detection method and kit comprising same

"The invention discloses an in vitro method for the identification of Candida albicans, the sequences associated to said identification, as well as diagnosis kits for identifying Candida albicans.""La invención describe un método in vitro de identificación de Candida albicans, las secuencias asociadas a dicha identificación, así como kits de diagnóstico para identificar Candida albicans.

In vitro method for the detection of Candida glabrata, diagnostic kit and use thereof

"La presente invención describe y reclama un método in vitro para la identificación de Candida glabrata, las secuencias asociadas a dicha identificación, así como kits de diagnóstico para identificar a C. glabrata y el uso de los mismos.""The present invention describes and claims an in vitro method for the identification of Candida glabrata, the sequences associated with said identification, together with diagnostic kits for identifying C. glabrata and the use thereof.

Adhesins in Candida glabrata

"The human fungal pathogen Candida glabrata is causing more and more problems in hospitals, as this species shows an intrinsic antifungal drug resistance or rapidly becomes resistant when challenged with antifungals. C. glabrata only grows in the yeast form, so it is lacking a yeast-to-hyphae switch, which is one of the main virulence factors of C. albicans. An important virulence factor of C. glabrata is its capacity to strongly adhere to many different substrates. To achieve this, C. glabrata expresses a large number of adhesin-encoding genes and genome comparisons with closely related species, including the non-pathogenic S. cerevisiae, which revealed a correlation between the number of adhesin-encoding genes and pathogenicity. The adhesins are involved in the first steps during an infection; they are the first point of contact with the host. For several of these adhesins, their importance in adherence to different substrates and subsequent biofilm formation was demonstrated in vitro or in vivo. In this review, we provide an overview of the role of C. glabrata adhesins during adhesion and biofilm formation both, under in vitro and in vivo conditions.

yKu70/yKu80 and Rif1 regulate silencing differentially at telomeres in Candida glabrata

"Candida glabrata, a common opportunistic fungal pathogen, adheres efficiently to mammalian epithelial cells in culture. This interaction in vitro depends mainly on the adhesin Epa1, one of a large family of cell wall proteins. Most of the EPA genes are located in subtelomeric regions, where they are transcriptionally repressed by silencing. In order to better characterize the transcriptional regulation of the EPA family, we have assessed the importance of C. glabrata orthologues of known regulators of subtelomeric silencing in Saccharomyces cerevisiae. To this end, we used a series of strains containing insertions of the reporter URA3 gene within different intergenic regions throughout four telomeres of C. glabrata. Using these reporter strains, we have assessed the roles of SIR2, SIR3, SIR4, HDF1 (yKu70), HDF2 (yKu80), and RIF1 in mediating silencing at four C. glabrata telomeres. We found that, whereas the SIR proteins are absolutely required for silencing of the reporter genes and the native subtelomeric EPA genes, the Rif1 and the Ku proteins regulate silencing at only a subset of the analyzed telomeres. We also mapped a cis element adjacent to the EPA3 locus that can silence a reporter gene when placed at a distance of 31 kb from the telomere. Our data show that silencing of the C. glabrata telomeres varies from telomere to telomere. In addition, recruitment of silencing proteins to the subtelomeres is likely, for certain telomeres, to depend both on the telomeric repeats and on particular discrete silencing elements.

Molecular characterization of the silencing complex SIR in Candida glabrata hyperadherent clinical isolates

"An important virulence factor for the fungal pathogen Candida glabrata is the ability to adhere to the host cells, which is mediated by the expression of adhesins. Epa1 is responsible for ?95% of the in vitro adherence to epithelial cells and is the founding member of the Epa family of adhesins. The majority of EPA genes are localized close to different telomeres, which causes transcriptional repression due to subtelomeric silencing. In C. glabrata there are three Sir proteins (Sir2, Sir3 and Sir4) that are essential for subtelomeric silencing. Among a collection of 79 clinical isolates, some display a hyperadherent phenotype to epithelial cells compared to our standard laboratory strain, BG14. These isolates also express several subtelomeric EPA genes simultaneously. We cloned the SIR2, SIR3 and SIR4 genes from the hyperadherent isolates and from the BG14 and the sequenced strain CBS138 in a replicative vector to complement null mutants in each of these genes in the BG14 background. All the SIR2 and SIR4 alleles tested from selected hyper-adherent isolates were functional and efficient to silence a URA3 reporter gene inserted in a subtelomeric region. The SIR3 alleles from these isolates were also functional, except the allele from isolate MC2 (sir3-MC2), which was not functional to silence the reporter and did not complement the hyperadherent phenotype of the BG14 sir3?. Consistently, sir3-MC2 allele is recessive to the SIR3 allele from BG14. Sir3 and Sir4 alleles from the hyperadherent isolates contain several polymorphisms and two of them are present in all the hyperadherent isolates analyzed. Instead, the Sir3 and Sir4 alleles from the BG14 and another non-adherent isolate do not display these polymorphisms and are identical to each other. The particular combination of polymorphisms in sir3-MC2 and in SIR4-MC2 could explain in part the hyperadherent phenotype displayed by this isolate.

Photo-assisted inactivation of Escherichia coli bacteria by silver functionalized titanate nanotubes, Ag/H2Ti2O5H2O

"One-dimensional titanate nanotubes (H2Ti2O5·H2O) functionalized with silver nanoparticles (AgNPs) exhibited unique properties for the effective inactivation of the Gram-negative Escherichia coli within 45 minutes under irradiation using a 65 W halogen lamp. The pathway of the photo-assisted catalytic inactivation was examined by SEM and TEM using a reproducible biological protocol for sample preparations. The membrane integrity of the bacteria was damaged due to the oxidative stress caused by the reactive oxygen species, the bacteriostatic effect of the highly-dispersed-surface AgNPs (∼5 nm) and the sharp nanotube penetration that induced the cell death.